Drier.



A. HOFFMANN.

} I DRIER. AP PIIIOATION I ILED JULY 6, 1912.

Patented May 13, 1913.

- 2 SHEETS-11311! 1.

COLUMBIA PLANOGRAPH co..WA$HlNn O D. c

A. HOFPMANN.

DRIER.

APPLICATION TILHUJULY 6, 1912.

Patented May 13, 1913.

2 SHEETS-SHEET 2.

COLUMBIA PLANOGRAPH 60., WASHINGTON, D. c.

UNITED STATES PATENT OFFICE.

ALEXANDER HOFFMANN, OF BALTIMORE, MARYLAND, ASSIGNOR OF DEMAREST LOWE,OF NEW YORK, N. Y.

ONE-HALF TO I.

DRIER.

Specification of Letters Patent. Paigented May 13, 1913.

AppIication filed July s, 1912. Serial No. 708,012.

To all whom it may concern I avoided thereby preserving the virtues ofthe product and the resultant increase in its value.

A further object is to provide an lmproved construction of drier wherebythe various odors usually passing therefrom may be passed through thefurnace if desired and thereby the objectionable odors be el1m1- nated.

A still further object is to provide an 1mproved drier in which heatunits may be drawn from the stack of a boiler, passed beneath thematerial tobe dried; then caused to travel over the material in adirection reverse to that in which the material is traveling and forcedback through the furnace or discharged into another stack, and anotherobject is to provide a machine which shall be automatic and continuousin its operation to dry materials fed thereto.

\Vith these'and other objects in view, the accompanying drawingsillustrate the invention wherein Figure 1, shows the lmprovedapparatuspartly in sideelevation and partly in sectional elevation, Fig. 2,illustrates a longltudmal sectional plan of the drier proper. Flg. 3,shows a longitudinal sectional elevation of the same. 4, illustrates anend elevation of the drier proper, and Fig. 5, a vertical crosssectional detail through the same.

Referring to the drawings by numerals, 1, designates the shell, casingor wall of the drier proper, which may be; constructed of brick,concrete or other suitable material and preferably has an arched orcurved upper portion, 2, which diminishes in height from the feed end,3, toward the discharge end, 1. 'A partition plate or wall, 5, extendslongitudinally and horizontally. between the ends of the drier and onthe interior thereof whereby to producea lower longitudinal.

chamber, 6, and an upper longitudinal chamber, 7,the two chambers beingin communication at oradjacent to thedischarge end by means of verticalside passages, 8. At

the feed-end, 8, the drier is closed by a vertical plate, 9, and thedischarge-end is provided with another plate, 10, which "effects aclosure of that end. A feed trough, 11, extends longitudinally throughthe drier and has side flanges, 12, which rest upon the horizontalpartition plates, 5, so as to allow the curved bottom, 18, of the troughto de pend into the lower longitudinal chamber, 6, of the drier. Theupper side of the trough is open and is in direct communication with theupper longitudinal chamber, 7, of the drier. At the discharge-end of thedrier, the trough extends through an opening in the plate, 9, and theprojecting end thereof has an opening, 14:, for the escape or dischargeof the dried material. A screw conveyer, 15, extends through the trough,11, and at the feed end the shaft of this conveyer passes through abearing, 16, and car-- ries a sprocket, 17, around which a drive chain,18, passes to effect a rotation of the sprocket and the screw conveyer.Suitable supports, 19, are provided in the lower chamber, 6, of thedrier to aid in sustaining the trough, 11, and steam heating pipes, 20,are also provided'in said chamber whereby to aid in heating the latter.A conduit, 21, communicates with the lower chamber, 6, said conduitextending between said chamher and the stack, 22, of a steam boiler, as

shown in Fig. 1.- An exhaust conduit, 23,

is attached to the front plate, 9, and communicates with the upperchamber, 7, of the drier and said exhaust conduit leads to an exhaustmotor or fan, 24,the latter being driven in any suitablemanner, such asby means of a pulley, 25, around which a belt will be passed.

A feed hopper, 26, is conveniently located at the side of the drier anda feed screw, 27, carried in atrough, 28, serves to convey the materialfrom the hopper and deposit it in the trough, 11, on the interior of thedrier where scrcw-conveyer, 15, will advance it through the dryingchamber during the drying operation. The feed screw, 27 in the presentinstance, is driven by means of bevel gears, 29, and, 30,the latterbeing carried 011 a driving shaft, 31, which is revolved by means of apulley, 32. The shaft, 31, also carries a sprocket, 33, around which thechain, 18, passes, so that motion may be conveyed from shaft, 31, to thescrew conveyer in the drier.

By referring to Fig. 1, it will be noted that a conduit, 34, leads awayfrom the exhaust motor or fan and that from that conduit two branchconduits, 35, and, 36, are provided which lead to the ash pits offurnaces, 37, and, 38, respectively. The branch, 36, is provided with avalve or damper, 39, whereby communication between furnace, 38, andconduit, 34, may be cut off or established as desired, and a similarvalve or damper, 40, enables communication to be established or cut offbetween furnace, 37, and branch, 35. Another branch conduit, 41, extendsfrom branch, 35, and enters the stack, 42, of furnace, 37, and a damperor valve, 43, in this branch, 41, serves to cut the same off frombranch, 35. It will thus be seen that by closing valves, 40, and, 43,and opening valve, 39, the exhaust from the drying chamber, 7, will bedrawn off by the motor or fan and conveyed by conduit, 34, and branch,36, to furnace, 38, where the exhaust vapors will pass up through thefire and thence to the stack, 22. Or, if desired, valves, 39, and, 43,may be closed and the exhaust vapors then conveyed by branch, 35, to thefurnace, 37, or by closing valves, 39, and, 40, and opening valve, 43,the ex hause may be sent to the stack, 42.

In operation, the material to be dried will be dumped into hopper, 26,and conveyed by screw, 27, to the trough, 11, in the drying chamber. Thescrew conveyer, 15, will then slowly move the material through thetrough toward the discharge end of the latter, during which time themotor or fan will operate. The action of this motor or fan creates asuction in conduit, 23, so as to draw the vapors and gases from thechamher, 7, into conduit, 23. This suction draws the heat units fromstack, 22, through conduit, 21, into the lower chamber, 6, of the drier,admitting the heat in the lower chamber at the feed end of the drier andwill act on the lower side of the conveyer trough, 11. The heat is thendrawn up through the passages, 8, adjacent to the discharge end of thedrier and into the upper drying chamber, 7, where the heat will bebrought into direct contact with the material in the trough. The heatpassing up through passages, 8, will be free of vapors that afterwardare given off from the material being dried, and acts on the driest ofthe material first. The heat then passes over the material, picking upthe moisture and vapors and is sucked out of the chamber, 7, at the feedend where the moisture'and vapor is greatest. By this means the moistureladen heat is not passed over or brought into contact with the driest ofthe materials consequently the latter passes from the conveyer in a muchdrier condition. As hereinbefore explained the exhaust may be carried toone or the other of the furnaces where its passage through the fire willfree it of practically all the noxious odors. It will thus be seen thatthe motor or fan creates a suction at the feed end of drying chamber, 7,which draws the heat units from the stack or other point of heat supplyand causes the heat to travel through chamber, 6, beneath the material,then up into chamber, 7, and over the material at the discharge end andto thereby apply the greatest heat to the driest of-the material first,and preventing the moisture and vapor given off by the incoming materialfrom passing over that ma terial from which the moisture has passed.

Having thus described my invention what I claim and desire to secure byLetters Patent is Y 1. In a drier the combination with a furnace havinga fire box and also having a stack, of a shell detached with respect tothe fire-box of the furnace and having a feed-end and a discharge-end;means forconveying material through the shell from the feed to thedischarge-end; means for conveying gases and heat from the stack to thedischarge-end of the shell and means for drawing the gases and heat fromthe said stack through the conveying chamber.

2. In a drier the combination with a furnace having a fire-box and astack, of a drying shell detached with respect to'the firebox of thefurnace and having a lower chamber and an upper chamber; means forconveying material through the upper chamber of the shell; connectionsbetween the lower chamber of the shell and the stack of the furnace andmeans connected with the upper chamber of the shell for expelling thestack gases and heat from said upper chamber.

3. In a drier the combination with a furnace having a fire-box and astack, of a drying shell detached with respect to the furnace and havinga lower chamber and an upper chamber which communicate at one end; atrough extending through the shell; a conveyer in said trough; means forestablishing communication between the stack of the furnace and thelower chamber of the shell beneath the feed-end of said trough and meansconnected with the upper chamber and above the feed-end of the saidtrough for expelling the stack gases and heat from said upper chamber.

4. In a drier the combination with a shell having a lower chamber and anupper chamber and the latter chamber being larger at one end than theother and being in communication with the lower chamber at its smaller,end, of means for conveying material through the upper chamber in adirection from the larger to the smaller end; means connected with thelarger end of the upper chamber for creating a suction therein and meansfor supplying heat to the lower chamber.

5. In a drier the combination with a'furnace having a fire-box and astack of a drying shell detached with respect to'the furnace and havinga lower chamber and a tapering upper chamber with a communicationbetween the smaller end of the upper chamber and said lower chamber;means for conveying material through upper tapering chamber towardthesmaller end of the 15 pelling the stack gases and heat from the 20said upper chamber. I

In testimony whereof I aifix my s1gnature in presence of two witnesses.

ALEXANDER HOFFMANN.

Witnesses I G. FERD. VoG'r, CHAs. B. MANN.

' copiel of thil patent may be obtained for five cents each, byaddressing the Commissioner of Patents,

' Washington, D. G.

